Do I go to my regualr hairdressers or the one giving me a good offer?

If you are happy with your regular stylist and the way your hair looks, stick with him/her. It's embarrassing to get butchered at a new place, then have to crawl crying back to the old place for correction.

I would only change stylists if you're unhappy with your current stylist. Specially if they're not being as attentive as they used to. I would try them out, give them pictures of the cut and colour that you're after.

Some times a change can be a good thing. If they do a horrible job you can always go back to your regular stylist.

You get why you pay for so I would say go to your regular hairdresser